The present invention relates to a shelving structure, more particularly, to a vertical framework extendable in both lateral and longitudinal directions. The shelving structure of the present invention can be assembled without any additional members such as screws or bolts and without the aid of tools other than a small mallet.
There have been proposed various types of knockdown shelving structures. For example, U.S. Pat. No. 3,244,127 issued Apr. 5, 1966 to Robert J. Evans discloses a knockdown type cantilever shelving. Shelvings can be installed at the both sides of the central posts. The shelving is extendable longitudinally but it is not extendable in front to rear direction. U.S. Pat. No. 3,693,556 issued Sept. 26, 1972 to Pierre Rous discloses sectional shelvings employing vertical uprights, each upright consisting of a member having in horizontal section or cross-sectional view the general shape of a hollow "T" of which the wing corresponding to the upper branch of the T is adapted to be positioned on the corresponding face of the shelving, the two walls of the central leg of the T constituting this hollow section being provided with a series of regularly spaced perforations throughout the height or length of the upright. The sectional shelvings according to U.S. Pat. No. 3,693,556 is extendable in longitudinal direction only. The Rous U.S. Pat. No. 3,487,790 issued Jan. 6, 1970 is also of that type.
U.S. Pat. No. 3,672,515 issued June 27, 1972 to Pierre Rous discloses a shelving structure which is extendable both in the longitudinal and in the front-to-rear directions. The shelving structure of U.S. Pat. No. 3,672,515 employs uprights interconnected by longitudinal and cross members having at both ends thereof a fastening inner plate which has a pair of fastening lugs adapted to fit the perforations provided in the corresponding upright.
The principal object of the present invention is to provide a knockdown type shelving structure which is extendable in both lateral and longitudinal directions and which can be easily assembled or disassembled without any additional members and without any specialized tools.
Another object of the present invention is to provide such a shelving structure as above which is adaptable for assembling heavy duty storage racks of various sizes.